Tetravinyl paint composition and painting process

ABSTRACT

A SUBSTRATE IS COATED WITH A FILM-FORMING COMPOSITION COMPRISING UNIQUE TETRAVINYL COMPOUND AND THE COATING IS CONVERTED TO A TENACIOUSLY ADHERING, SOLVENT-RESISTANT, WEAR-AND-WEATHER-RESISTANT COATING BY EXPOSING THE COATED SUBSTRATE TO IONIZING RADIATION, PREFERABLY IN THE FORM OF AN ELECTRON BEAM. THIS TETRAVINYL COMPOUND IS FORMED BY FIRST REACTING A DIEPOXIDE WITH ACRYLIC ACID AND/ OR METHACRYLIC ACID AND SUBSEQUENTLY REACTING THE RESULTANT ESTER CONDENSATION PRODUCT WITH A VINYL UNSATURATED ACYL HALIDE.

Patented b. H H 3 586,526 TETRAVINYL PAINT COMPOSITION AND f- PAINTING PROCESS H ..CC O C O C C C H Elihu J. Aronolf, Framingham, Mass., and Santokh S. I

Labana, Dearborn Heights, Mich., assignors to Ford Motor Company, Dearbom, Mich. H H

Filed Aug. 4, 1969, Ser. No. 847,324 Int. Cl. B44d 1/50; C08f 1/24; C07c 69/52 0. H H H\ /H vs. C]. 111-9331 Claims H 0 H 0 H H C 0 e o :1 'e C ABSTRACT OF THE DISCLOSURE \i l H H H l l) A substrate is coated with a film-forming composition H3O comprising unique tetravinyl compound and the coating 15 is converted to a tenaciously adhering, solvent-resistant, H H H H wear-and-weather-resistant coating by exposing the coated substrate to ionizing radiation, preferably in the other Suitable dlepoxldes are dlsclosed In Patsform of an electron beam. This tetravinyl compound is 2; 3,256,226; 3,373,221 and elsewhere g formed by first reacting a diepoxide with acrylic acid and/ 2 out the t i or methacrylic acid and subsequently reacting the re- T dIePoXIdeS employed will usually e moieellial sultant ester condensation product with a vinyl unsaturated Weights below about more C mmonly 1n the range acyl halide. of about 140 to about 500. Usually, the d1pOXldCS will consist of carbon, hydrogen and oxygen but they may be II t t th t f It substituted, if desired, with non-interfering substituents, 1S mven Ion e 2 0 e at o 15 such as halogen atoms, ether radicals and the like. They ticularly concerned with a process of painting a substrate may be Saturated or unsaturated aliphatic, cycloaliphatic, mg sgi ig rariltlhsgrgaiesfgfm'vgfii,2 3:1135 gig aromatic or heterocyclic. They may be monomeric or 0 meme. vinyl compounds and crosslinking such film former into 3 p Vinyl unsaturated acyl halides are preferably T P gi' g y h a gr l i hgni hgg' acryloyl chloride and/ or methacryloyll) chloriide but others 1 3 a mug exposmg 6 same 1 121 may be used e.g. the corresponding romi es. radiatlon, preferably n the form of an electron beam, and The resultant tetravinyl compounds used herein are to 31 f f i tg izi'm a nt is meant to in homopolymerizable and copolymerizablle Wlih monoi ahnd 1ca1o 1 and/Grady wi 311a serrate $222111, asthma; out plgment and or filler or havmg very little of the sam ethyl acrylate, butyl acrylate, butyl methacrylate, hydroxyg f tmted 1f g g- 3. propyl methacrylate, glycidyl methacrylate, etc., the di- W tlmfately cross m by lomzmg Ta latlon VlIlYl reaction product formed by reacting monoepox de can be all or Vlrtually all that 15 used to form the 40 with acrylic acid or methacrylic acid and then reacting it can be a Vehicle for Pigment and/or Particulate the resultant product with a 'vinyl unsaturated acyl hafi material lide the divinyl reaction product formed by reacting a The first reaction p in Preparing the tetravinyl diepoxide with two molar parts of acrylic acid or methpounds used herein is illustrated by the representative acrylic acid, the di i l reaction d t f d by reaction shown in FIG- 1 0f the accompanying drawingreacting a diepoxide with two molar parts of acrylic The Seeohd reaction p is illustrated y the represehta' acid or methacrylic acid and subsequently reacting the tive reaction shown in FIG. 2. resultant ester condensation product with two molar parts The diePoXideS p y as Starting materials for of a saturated acyl halide, e.g., acetyl chloride or an paring the tetravinyl o po of this ihvelitiohihay be ellectively saturated acyl halide, e.g., benzoyl chloride, of the epiohiorohydrlh'blsphehoi yP the p f o the divinyl reaction product formed by reacting one y -p yp these P p by reacting molar part of a diepoxide with two molar parts of OlefinS With Peliaeids, Peraeetic acid, or other meehsacrylic or methacrylic acid and subsequently reacting DiePoXideS and their Preparation are discussed in detail in the resultant ester condensation product with two molar MOderIl Surface Coatings, Paul Nyieh and Edward S1111 parts of an alpha-beta olefinically unsaturated acyl halide derlalld, 1965 Science Publishers, a division Of John having an aromatic radical affixed to the beta carbon Wiley & Soils Lohdoh"NeW y y Library of 0f the olefinic linkage, e.g., cinnamic acid chloride, alpha- Cohgress Catalog Card Number PP- beta olefinically unsaturated polymers, etc. Representative diePoXideS include, not y y of iimi" The tetravinyl adducts used herein have lower viscositation, the following: ties than their corresponding divinyl compounds pro- (1) 3,4 epoxy 6-methyl-cycloheXylmethyl-3,4-epoxyduced by reacting one mole of diepoxide with two moles methylcyclohexanecarboxylate. 60 of acrylic acid or methacrylic acid. In relation to such (2) 1-epoxyethyl-3,4-epoxycyclohexane. divinyl compounds, the tetravinyl compounds are also (3) dipentene dioxide (limonene dioxide). more sensitive to ionizing radiation and have increased (4) dicyclopentadienedioxide. solubility in organic solvents. (5) 'diepoxides having structural formula in accord 5 A minor portion, i.e. up to slightly below about 50 ance with the following: 6 weight percent of the tetravinyl compound may be replaced With a divinyl compound consisting essentially of carbon, hydrogen and oxygen and having a molecular a. H H H H H H III weight below about 2,600, preferably about 220 to about I I l I 1,100, more preferably about 220 to about 650, such H C/CC O(C )OCC/C H as one of the divinyl compounds hereinbefore mentioned I l I o H H H 0 and hereinafter illustrated.

The films formed from the paints of this invention are advantageously cured at relatively low temperatures, e.g. between room temperature (20 to 25 C.) and about 70 C. The radiation energy is applied at dose rates of about 0.1 to about 100 Mrad per second upon a preferably moving workpiece until the wet film is converted to tack-free state or until the film is exposed to a desired dosage.

The film-forming material advisedly has an application viscosity low enough to permit rapid application to the substrate in substantially even depth and high enough so that at least 1 mil (0.001 inch) film will hold upon a vertical surface without sagging. Such films will ordinarily be applied to an average depth of about 0.1 to about 4 mils with appropriate adjustment in viscosity and application technique. It will be obvious to those skilled in the art that the choice of diepoxide used in preparing the tetravinyl compound can be varied so as to vary the viscosity of the resultant product. Likewise, the viscosity of the total film-forming composition can be varied by the choice of other polymerizable components of the coating composition. The viscosity can also be adjusted by the addition of nonpolymerizable, volatile solvents, e.g., toluene, xylene, etc., which can be flashed olf after application. By one or more of such adjustments, the viscosity of the paint binder solution can be adapted for application by conventional paint application techniques, e.g. spraying, roll coating, etc. The paint binder is preferably applied to the substrate and cured thereon as a continuous film of substantially even depth.

This invention will be more fully understood from the following illustrative examples.

EXAMPLE 1 A tetravinyl compound is prepared in the manner below set forth from the materials hereinafter named:

1) To a reaction vessel equipped with condenser, stirrer, nitrogen inlet and thermometer are charged the following materials:

, Parts by wt.

(a) Diepoxide 192 (b) Methacrylic acid 86 (c) Toluene (solvent) 500 (d) Dimethyl benzylamine (catalyst) 1 r r a? (2) The diepoxide, the methacrylic acid and the dimethyl benzylamine are intimately mixed and incrementally added to the toluene which is at 90 C. in a nitrogen atmosphere.

(3) The reaction mixture is maintained at 90 C. until reaction of the epoxide groups is essentially complete as measured by a product acid number of less than about 10.

(4) The solvent is removed under vacuum and a solid reaction product (softening point 45 C.) is recovered.

(5) The solid reaction product of (4) in the amount of 280 parts by weight is dissolved in 500 parts by weight toluene, and 110 parts by weight of methacryloyl chloride are added dropwise with the reaction mixture maintained at 65 C. until HCl evolution ceases.

(6) The solvent is removed under vacuum and a tetravinyl compound is recovered in the form of a viscous liquid.

Substrates of wood, glass, metal and polymeric solid, i.e. polypropylene and acrylonitrile-butadiene-styrene copolymer, are coated with this tetravinyl compound using the following procedure:

(1) The above prepared tetravinyl compound is diluted to spraying viscosity with xylene and a paint film is EXAMPLE 2 The procedure of Example 1 is repeated except that the diepoxide employed is 3,4-epoxy-6-methyl cyclohexylmethyl-3,4-epoxymethyl cyclohexanecarboxylate.

EXAMPLE 3 The procedure of Example 1 is repeated except that the diepoxide empolyed is 1-epoxyethyl-3,4-epoxycyclohexane.

EXAMPLE 4 The procedure of Example 1 is repeated except that the diepoxide employed is dipentene dioxide.

EXAMPLE 5 The procedure of Example 1 is repeated except that the diepoxide employed is dicyclopentadienedioxidc.

EXAMPLE 6 The procedure of Example 1 is repeated except that the diepoxide employed has structural formula in accordance with the formula hereinbefore set forth and identified as diepoxide (5)a wherein n is 4.

EXAMPLE 7 The procedure of Example 1 is repeated except that the diepoxide employed has structural formula in accordance with the formula hereinbefore set forth and identified as diepoxide (5)12.

EXAMPLE 8 The procedure of Example 1 is repeated except that the diepoxide employed has structural formula in accordance with the formula herein'before set forth and identified as diepoxide (5 c wherein n is 4.

EXAMPLE 9 The procedure of Example 1 is repeated with the sole difference that the electrons of the electron beam have an average energy of about 350,000 electron volts.

EXAMPLE 10 The procedure of Example 1 is repeated with the sole d1fference that the atmosphere of irradiation is helium.

EXAMPLE 11 The procedure of Example 1 is repeated with the sole difference that acryloyl chloride is substituted for the methacryloyl chloride.

'EXAMPLE 12 The procedure of Example 1 is repeated with the sole difference that methacryloyl bromide is used in lieu of methacryloyl chloride.

EXAMPLE 13 The procedure of Example 1 is repeated with the sole difference that acryloyl bromide is substituted for the methacryloyl chloride.

EXAMPLE 14 The procedure of Example 1 is repeated with the sole diiference that the diepoxide is first reacted with a mixture of acrylic acid and methacrylic acid.

EXAMPLE 1s A tetravinyl compound is prepared as in Example 1 and a divinyl compound is prepared using the same procedure with the single exception that butyric acid chloride is substituted for the second stepreactant methacryloyl chloride used in the preparation of the tetravinyl compound. Substrates are then coated as in Example 1 using a paint binder composition consisting of 51 parts by weight of the tetravinyl compound, 49 parts by weight of the divinyl compound, and acetone in an amount sufficient to provide the composition with good spraying viscosity. The substrates are coated with this composition and the acetone flashed off prior to irradiaation. Irradiation conditions are the same as in Example 1.

Additional substrates are coated in like manner except that the paint binder composition consists of 99 parts by weight of said tetravinyl compound, 1 part by weight of said divinyl compound, and said acetone.

Additional substrates are coated in like manner except that the paint binder composition consists of 75 parts by weight of said tetravinyl compound, 25 parts by weight of said divinyl compound, and said acetone.

EXAMPLE 16 A tetravinyl compound is prepared as in Example 1 and a divinyl compound is prepared using the same procedure with the single exception that cinnamic acid chloride is substituted for the second step reactant methacryloyl chloride used in preparation of the tetravinyl compound. Substrates are then coated as in Example 1 using a paint binder composition consisting of 51 parts by Weight of the tetravinyl compound, and toluene in an amount sufficient to provide the composition with a good spraying viscosity. The substrates are coated with this composition and the toluene flashed otf prior to irradiation. Irradiation conditions are the same as in Example 1.

Additional substrates are coated in like manner except that the paint binder composition consists of 99 parts by weight of said tetravinyl compound, 1 part by weight of said divinyl compound, and said toluene.

EXAMPLE 17 A tetravinyl compound is prepared as in Example 1 and a divinyl compound is prepared using the same procedure with the single exception that '1 molar part of cyclopentene oxide is reacted with 1 molar part of methacrylic acid to open the epoxide ring and provide a monovinyl compound and then the resultant ester condensation product is reacted with methacryloyl chloride to provide a divinyl compound. Substrates are coated as in Example 1 using a paint binder composition consisting of 51 parts by weight of the tetravinyl compound, 49 parts by weight of the divinyl compound, and xylene in an amount sufiicient to provide the composition with good spraying consistency. The substrates are coated with this composition and the xylene flashed ofi prior to irradiation. Irradiation conditions are the same as in Example 1.

Additional substrates are coated in like manner except that the paint binder composition consists of 99 parts by weight of said tetravinyl compound, 1 part by weight of said divinyl compound, and said xylene.

EXAMPLE 18 A tetravinyl compound is prepared as in Example 1 and a divinyl compound is prepared using the same procedure employed in the first step of preparing the tetravinyl compound. Substrates are coated as in Example 1 using a paint binder composition consisting of 51 parts by weight of said tetravinyl compound, 49 parts by weight of said divinyl compound, and xylene in'an amount suflicient to provide the composition with good spraying consistency. The substrates are coated with this composition and the xylene flashed off prior to irradiation. Irradiation conditions are the same as in Example 1.

Additional substrates are coated in like manner except that the paint binder composition consists of 9-9 parts by weight of said tetravinyl compound, 1 part by weight of said divinyl compound, and said xylene.

EXAMPLE 19 The procedure of Example 15 is repeated except for the sole difference that benzoyl chloride is substituted for the but ric acid chloride.

The term ionizing radiation as employed herein means radiation having sufiicient energy to effect polymerization of the paint films herein disclosed, i.e., energy equivalent to that of about 5,000 electron volts or greater. The preferred method of curing films of the instant paints upon substrates to which they have been applied is by subjecting such films to a beam of polymerization effecting electrons having an average energy in the range of about 100,000 to about 500,000 electron volts. When using such a beam, it is preferred to employ a minimum of 25,000 electron volts per inch of distance between the radiation emitter and the workpiece when the intervening space is occupied by air. Adjustment can be made for the relative resistance of the intervening gas which is preferably an oxygen-free inert gas such as nitrogen or helium.

The abbreviation rad as employed herein means that dose of radiation which results in the absorption of ergs of energy per gram of absorber, e.g. coating film. The abbreviation Mrad as employed herein means 1 million rad. The electron emitting means maybe a linear electron accelerator capable of producing a direct current potential in the range of about 100,000 to about 500,000 volts. In such a device electrons are ordinarily emitted from a hot filament and accelerated through a uniform voltage gradient. The electron beam, which may be about /s inch in diameter at this point, may then be scanned to make a fan-shaped beam and then passed through a metal window, e.g. a magnesium-thorium alloy, aluminum, an alloy of aluminum and a minor amount of copper, etc., of about 0.003 inch thickness.

It will be understood by those skilled in the art that modifications can be made within the foregoing examples without departing from the spirit and scope of the invention as set forth in the following claims.

What is claimed is:

1. A paint polymerizable by ionizing radiation which, exclusive of nonpolymerizable solvents, pigments and particulate mineral filler, consists essentially of a tetravinyl compound formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant divinyl ester condensation product with two molar parts of a vinyl unsaturated acyl halide.

2. A paint in accordance with claim 1 wherein said diepoxide has a molecular weight below about 2,000.

3. A paint in accordance with claim 1 wherein said diepoxide has a molecular weight in the range of about to about 500.

4. A paint in accordance with claim 1 wherein said acyl halide is the chloride of acrylic or methacrylic acid.

5. A paint in accordance with claim 1 wherein said acyl halide is the bromide of acrylic or methacrylic acid.

6. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound consisting essentially of carbon, hydrogen and oxygen and having a molecular weight below about 2,600.

7. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound having a molecular weight below about 2,600 and formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant ester condensation product with two molar parts of a saturated acyl halide.

8. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound having a molecular weight below about 2,600 and formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic'acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant ester cond ensation product with two molar parts of an alpha-beta olefinically unsaturated acyl halide having an aromatic radical afilxed to the beta carbon of the olefinic linkage.

9. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound having a molecular weight below about 2,600 and formed by reacting one molar amount of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid.

10. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced With a divinyl compound having molecular Weight below about 2,600 and formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant condensation product with two molar par-ts of an aromatic substituted saturated acyl halide.

11. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound consisting essentially of carbon, hydrogen and oxygen and having a molecular Weight in the range of about 220 to about 1100.

12. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound consisting essentially of carbon, hydrogen and oxygen and having a molecular weight in the range of about 220 to about 650.

13. A paint in accordance with claim 1 wherein an amount up to but less than 50% of said tetravinyl compound is replaced with a divinyl compound having a molecular Weight in the range of about 220 to about 650 and formed by reacting a monoepoxide with an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylicacid and methacrylic acid and then reacting the resultant ester condensation product with a vinyl unsaturated acyl halide.

14. In a method for painting a substrate wherein a cfilmforming solution is applied as a paint film to a surface of said substrate and crosslinked thereon by exposing the coated surface to ionizing radiation, the improvement wherein said film-forming solution, exclusive of nonpolymerizable solvents, pigments and particulate mineral filler, consists essentially of a tetravinyl compound formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant divinyl ester condensation product with two molar parts of a vinyl unsaturated acyl halide.

15. An article of manufacture comprising in combination a substrate and a polymerized coating of paint formed upon an external surface thereof by applying to said surface a film of substantially even depth of a film-forming solution which, exclusive of nonpolymerizable solvents, pigments and particulate mineral filler, consists essentially of a tetravinyl compound formed by first reacting one molar part of a diepoxide with two molar parts of an alpha-beta olefinically unsaturated monocarboxylic acid selected from acrylic acid and methacrylic acid and subsequently reacting the resultant divinyl ester condensation product with two molar parts of a vinyl unsaturated acyl halide, and cross-linking said film on said surface with ionizing radiation.

References Cited UNITED STATES PATENTS 3,466,259 9/1969 Jernigan 260-836X FOREIGN PATENTS 1,006,587 10/1965 Great Britain 260-486 ALFRED L. LEAVITT, Primary Examiner J. H. NEWSOMIE, Assistant Examiner us. (:1. X.R. 117138.8, 161; 204-15915, 159.16; 260-4106, 475, 485, 486, 835, 836, 857 

